[Sync] Remove DropAttachments from AttachmentService and SyncData

sync/internal_api/public/attachments/attachment_service_impl.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_ATTACHMENT_SERVICE_IMPL_H_
 #define SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_ATTACHMENT_SERVICE_IMPL_H_
 
 #include <deque>
 
 #include "base/memory/ref_counted.h"
@@ skipping 44 matching lines @@
                         const base::TimeDelta& max_backoff_delay);
   ~AttachmentServiceImpl() override;
 
   // Create an AttachmentServiceImpl suitable for use in tests.
   static scoped_ptr<syncer::AttachmentService> CreateForTest();
 
   // AttachmentService implementation.
   AttachmentStore* GetStore() override;
   void GetOrDownloadAttachments(const AttachmentIdList& attachment_ids,
                                 const GetOrDownloadCallback& callback) override;
-  void DropAttachments(const AttachmentIdList& attachment_ids,
-                       const DropCallback& callback) override;
   void UploadAttachments(const AttachmentIdSet& attachment_ids) override;
 
   // NetworkChangeObserver implementation.
   void OnNetworkChanged(
       net::NetworkChangeNotifier::ConnectionType type) override;
 
   // Use |timer| in the underlying TaskQueue.
   //
   // Used in tests.  See also MockTimer.
   void SetTimerForTest(scoped_ptr<base::Timer> timer);
 
  private:
   class GetOrDownloadState;
 
   void ReadDone(const scoped_refptr<GetOrDownloadState>& state,
                 const AttachmentStore::Result& result,
                 scoped_ptr<AttachmentMap> attachments,
                 scoped_ptr<AttachmentIdList> unavailable_attachment_ids);
   void WriteDone(const scoped_refptr<GetOrDownloadState>& state,
                  const Attachment& attachment,
                  const AttachmentStore::Result& result);
-  void DropDone(const DropCallback& callback,
-                const AttachmentStore::Result& result);
   void UploadDone(const AttachmentUploader::UploadResult& result,
                   const AttachmentId& attachment_id);
   void DownloadDone(const scoped_refptr<GetOrDownloadState>& state,
                     const AttachmentId& attachment_id,
                     const AttachmentDownloader::DownloadResult& result,
                     scoped_ptr<Attachment> attachment);
   void BeginUpload(const AttachmentId& attachment_id);
   void ReadDoneNowUpload(
       const AttachmentStore::Result& result,
       scoped_ptr<AttachmentMap> attachments,
@@ skipping 14 matching lines @@
 
   // Must be last data member.
   base::WeakPtrFactory<AttachmentServiceImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AttachmentServiceImpl);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_ATTACHMENT_SERVICE_IMPL_H_